In the 1990s, peer-to-peer networks were a revelation. They allowed people to pool together tiny parts of their computers, and those pooled together parts could do far more together than the average computer or connection could do on its own. It enabled everything from swapping pirated music to making cheap transcontinental calls via Skype.

But what if you could do the same thing with tiny parts of people’s day? Grab five to ten minutes here or there, at the right time and the right place, to complete a massive task no one person could do on his or her own. That’s exactly what a new startup called Gigwalk is trying to do, using the power of– you guessed it– the iPhone. You download the app, enter your PayPal information and get assigned entry level “gigs” or jobs that may take just a few minutes at a time, if you’re in the right location.

The first beta customer was the navigation company TomTom. No matter how much TomTom spends on a traditional salesforce, there will always be mistakes in its navigation– the one-way street, the surprise dead-end, the no left turn sign. These mistakes are an annoyance to users, but not fatal enough to the user experience for the company to invest millions in fact checking every street corner in the world. But if the company can pay someone already standing there $3 to snap a few pictures of the intersection in question and email them in, that changes everything.

You can imagine a lot of companies that could make use of a cheap, flexible mobile workforce paid just a few dollars at a time, no management costs or hassles involved. This mobile, non-committal workforce could do things like verifying that health-inspection scores are posted in restaurants, confirming product displays in stores are done right or even spot checking customer service. Co-founder and CEO Ariel Seidman suggested TechCrunch could use it as a mobile roster of embedded reporters; but as a publication that doesn’t pay for tips, even $3 is a dangerous precedent. I bet publications that do pay for tips would love it, though. No doubt, Gawker would pay for an army of $3-a-photo Gawker stalkers if they delivered the goods. (Lord help us all if they do.)

And you can see why data-obsessed Reid Hoffman jumped to invest in the company via Greylock’s Discovery Fund: All the information is geotagged, building a huge database of who does what tasks, how many tasks they complete and when they complete them. That can be used to recommend gigs, recommend workers to employers based on their productivity, or a host of other features to make the service work better for both parties. (Other investors include Jeff Clavier, Michael Dearing and the Founder Collective.)

Of course there’s one catch to all this: Do the millions of people with iPhones actually want to be part of that mobile workforce? Without users, Skype’s peer-to-peer network wouldn’t be very powerful. And without a broadly distributed base of “Gigwalkers”– as they’re called– this company won’t be either.

Seidman says there are different motivations for different people. Some college kids join the workforce for extra weekend spending money, others like being part of the community, he says. I don’t doubt either. My doubt is how many of them exist. For one thing, we’re not talking about a lot of money. Gigs can pay up to $90 each, but you have to do the low-level $3 ones frequently enough to unlock the higher paying jobs. “If people are smart about it, they can make an extra $50-$100 a month,” he says.

That reminds me of the people who clip coupons all year long, saving $.35 cents here or there. Sure, those savings add up to hundreds by the end of the year, or maybe even thousands. But it’s a pain. A minority of people have the discipline to get the micro-savings all year long. Many more lose interest, or just don’t feel the savings are great enough to make it worth their time and the hassle. Sure, economic times are still hard for many, as Seidman points out. But $50 isn’t going to pay the mortgage. And, let’s remember: People walking around with iPhones aren’t exactly out-of-work, lower-middle class Americans. Gigwalk wouldn’t even offset your AT&T bill.

I am not one of those people who loves the obsession with turning everything into a game, but if Gigwalk is going to build a large enough base of users to prove truly useful to big companies who need big problems solved, it’s going to need to appeal to more than just people’s wallets, raise the amounts paid-out, or build an app that works on basic feature phones.

The promise of Gigwalk reminds me of the open source boom in the mid-2000, where companies thought people would spend their weekends impassioned to make, say, ERP or CRM software better for free. Dozens of these companies were started and exactly zero lived up to the hype. MySQL was the only member of the open source stack that got a $1 billion outcome, and that was at an insane revenue multiple.

What sets true broad-based community efforts– like Wikipedia and Linux and even Firefox– apart are that there is a small base of people who do the heavy lifting and an army that does micro-work and evangelism. And, while I’m not sure how much this matters, it’s worth noting all three of those are non-commercial ventures.

Of course the Web is full of ideas that didn’t work the first fifty times, only to work brilliantly in the right incarnation with the right execution. There are two things that could make Gigwalk different. The first is that phone in your pocket at all times. If the company could make it absolutely drop-dead easy to make $3, I’d consider doing it. But that doesn’t just include an easy sign-up process. I would want something like an alert when I’m passing, say, an intersection that TomTom needs to make sure is really there. I don’t want to have to “plan” or “be smart about it.” I’ve got enough stuff in my life I need to plan around and be smart about– things that either pay me more than $3 or are worth more than an extra $3 to me.

The other big exception is a work force in the emerging world. Plenty of consumer-facing multinationals would love an army of kids to do street level market research or tasks throughout BRIC mega-markets, and $3 is a far more meaningful amount of money to people in emerging worlds. Of course, this opens up more problems: The payment issue is thornier when you get international, there’s a significant marketing and language challenges and there’s the iPhone-only problem. But that opportunity is massive. It’s not too different from how Giant Interactive, an online gaming company in China, used an army of kids to go into second and third tier cities, hang out in Internet cafes and talk up its game ZT Online. That almost manufactured grassroots approach made Giant a big, publicly traded company.

Five hundred of you have the chance to try it out for free. Go here and enter the code TCRUNCH to post a basic photo-request gig for free. Let us know how it works out. (The gigs are subject to the company’s approval; bear in mind it’s only operating in Los Angeles, San Francisco, New York City, Chicago, Philadelphia, Boston and Miami right now.)